This is a short demonstration of the Multi-Laser Gestural Interface (MLGI), an experimental music controller that looks like it could be Jean Michel Jarre's next toy.
The MLGI interface uses inexpensive 5mW red lasers, photocells, and Dan Overholt’s CREATE USB programmable interface (CUI) as the primary components of its circuit. The MLGI can send note on-off signals and continuous control messages.
The MLGI was designed by Meason Wiley at the California Institute of the Arts.
You can find more information, including a PDF describing how to build a MLGI, at cyclespersecond.net.